20–27 Mar 2026
Wild View Resorts
Africa/Gaborone timezone

Contribution of Compton-supported cascade emissions to broadband SEDs of $\gamma$-ray bright AGNi

Not scheduled
20m
Wild View Resorts

Wild View Resorts

Plot 80 President Avenue, Kasane, Botswana
In-person - Poster Presentation 10 S&E poster Science & Engineering

Speaker

Mfuphi Ntshatsha (University of Johannesburg)

Description

Active galactic nuclei (AGNi) are compact regions that emit throughout the electromagnetic spectrum. Blazars, a subclass of AGNi with their relativistic jets closely aligned with our line-of-sight, are especially powerful sources of $\gamma$-rays. Furthermore, the unified scheme for radio-loud AGNi classifies radio galaxies as the misaligned parent population of blazars. This would make them intrinsic producers of high-energy (HE, $E> 100$ MeV) and very high-energy (VHE, $E > 100$ GeV) $\gamma$-rays. However, early-generation observatories did not detect them at such high frequencies. It was understood that while emissions would be Doppler boosted in blazars, this would not be the case in radio galaxies. Recently, advances in $\gamma$-ray observatories have led to the detection of radio galaxies at these frequencies. To explain these emissions without relying on Doppler boosting, we leveraged a Monte-Carlo code that propagates $\gamma$-rays in an AGN environment, leading to secondary $\gamma$-ray and electron-positron pair cascades. In the code, we consider homogeneous external radiation from the broad-line region and anisotropic external radiation from a thin Shakura-Sunyaev accretion disk. In this work, we implement a toroidal magnetic field and compare the resulting spectral energy distributions to previous work where a uniform, static magnetic field was considered.

Stream Science or Engineering

Primary author

Mfuphi Ntshatsha (University of Johannesburg)

Co-authors

Prof. Markus Boettcher (North-West University) Soebur Razzaque (University of Johannesburg)

Presentation materials

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